Auger-bit



(ModeL) Y J. SWAN. AUGER. BIT.

Patented Aug. 14, 1883.

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NI-TED STATES.

PATENT O FIGE.

JAMEs SWAN, or sEYMoUn, CONNECTICUT.

AUGER-BIT. v

SPECIFICATIQIQ' forming part of Letters Patent No. 283,040, dated August 14, 1883.

Application filed May 16, 1883. (Model) To all whom .it may concern Be it known that I, JAMES SWAN, of Seymour, county of New Haven, State of Connecticut, have invented an Improvement in Auger- Bits, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts. i

p All twisted. auger-bits known to me as now constructed have what is called a leadingscrew, which draws the pod and cutting parts into the wood at a speed depending upon the pitch of the thread cut on the said leadingscrew, and the bit enters the wood at each turn only for a distance defined by the pitch of the said screw. This screw, besides retarding the entrance of the auger or bit, is also very objectionable'because it acts as a wedge and splits the wood. By experiment I have discovered that splitting of the wood may be obyiated by omitting the leading-screw and providing the bit with spurs to enter and produce 1 pod to be carried out of the hole.

an annular incision in the wood in advance of the action of the floor-lip, the latter merely acting to chip up the wood within the annular incision and deliver it into the grooves of the Omitting the leading-screw also results in leaving the wood in. a better condition to be chipped out, *for it is not compressed or hardened before the floor-lip strikes it, as is the case when the wood is wedged aside by the leading-screw. The inner cutting edgesof the floor-lip are extended substantially to the center or axial line of the bit, and act to draw the bit into the wood, as does the usual leading-screw. The leading-screw is also seriously objectionable when acting at an angle to the grain of the wood, as it is apt to be diverted from a straight line by the irregulargrain of the wood, thus frequently failing to bore a truly straight and' cylindrical hole.

To obviate this running,

ing-screw extra pressure exerted. on the bit enables it to be forced into the wood at each r0.- tation for a distance dependent almost entirely upon the amount of pressure so exerted, rather than upon the pitch of the leading-screw, as in common bits. One of my improved bits may be made to bore much more rapidly than were a leading screw employed, and. at the same time do as good work with no greater expenditure of power.

My invention consists in a spur-bit provided with spurs or cutters to first enter the wood, and having cutting-edges of itsfloor-lips extended inwardly to the center line of the bit, thus obviating the employment of the leading screw.

Figure l is a side elevation of an auger-bit embodying my invention; Fig. 2, another side view of part of the bit turned one-fourth round from Fig. 1; and Fig. 3 is an end view of the bit.

end of the 'pod is provided with two spurs, c c, which extend a little beyond the floor-lips (1, made at the end of the pod, as seen in Fig. 3, wherein it will be noticed that the edges of the floor-lip extend substantially to the center line or axial center of the pod, so that the wood within the circular incision made by the cut ters c is chipped out by the floor-lip, and the wood not being expanded and hardened by a leading-screw,-thefloor-lip readily cuts therein.

I claim As an improved article of manufacture, a twisted bit provided with spurs or cutters c, to first enter the wood, and having the edges of its floor-lip extended to the axial center of the bit, thus enabling the usual leading-screw to be omitted, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES swAN.

Witnesses:

A. B. Posr,

W. H. WHITTEMORE.

The pod a and shank b are all as usual. The 

